A rooftop support, such as that disclosed in U.S. Patent Publication 2011/0192941, can be constructed of two parts, an upper platform and a lower base, which are threadably connected.
The height of the rooftop support is increased by rotating the lower base about its central axis. However, if the base is rotated beyond the point at which it is securely attached to the upper platform, the upper platform and load which it supports can become unstable. A heavy load could potentially topple and injure the operator of the rooftop support.